Aligned electrode holders for mount-
ing parallel array of electron guns



June 28, 1966 J. H. JOHNSON 3,253,625

ALIGNED ELECTRODE HOLDERS FOR MOUNTING PARALLEL ARRAY 0F ELECTRON GUNS Filed July 27, 1964 -MMM WW ATTORNEYS United States Patent Office 3,258,525 Patented June 28, 1966 ALIGNED ELECTRODE HOLDERS FOR MOUNT- ING PARALLEL ARRAY OF ELECTRON GUNS Jay H. Johnson, Qwensboro, Ky., assignor to Kentucky Electronics Inc, Owensboro, Ky., a corporation of Kentucky Filed July 27, 1964, Ser. No. 385,309 6 Claims. (Cl. 313-69) This invention relates to electron guns used in cathode ray tubes and in particular it relates to multiple gun assemblies such as used in color television tubes.

It has been customary in the cathode ray tube art to employ in color tubes three electron gun assemblies designed for single-gun tubes as assembled in a battery or array tied together by brackets or mounting rods. Such techniques favor a high reject rate because of the large number of possibilities of misalignment of individual elements or the respective guns and the tedious procedures required for maintaining accurate positioning.

In plural gun color tubes the balance between the guns is critical to the production of the desired color, and the three guns must be matched carefully, whereas ordinary single tube guns need not be so carefully controlled. Thus, relatively minor displacements between electrodes in diiferent guns causing shifting of parts in a color assembly will result in an unacceptable color gun even if the individual guns were acceptable in a single gun tube.

Thus it is an object of the invention to provide an improved multiple beam electron gun.

Another object of the invention is to maintain uniformity between the beams of multiple-beam electron guns.

Thus in accordance with the present invention, the aforegoing problems are corrected by providing a multiple beam gun which assures accuracy of alignment of all beams during assembly of the various electrodes and guns involved. This is effected by providing integral insulated electrode holders which retain the corresponding electrodes for the various guns in fixed position within a set of apertures so that the electrodes for the different guns are relatively positioned in a matrix formed by the holder.

The above features and objectives of the invention are better understood from the following more detailed specification with reference to the accompanying drawing, wherein:

FIGURE 1 is an elevation view partly in section of a multiple-beam electron gun assembly incorporating the invention;

FIGURE 2 is a plan view of an insulated electrode holder afforded by the invention; and

FIGURE 3 is an elevation view of a further electron gun embodiment of the invention.

The multiple-beam electron gun of FIGURE 1 only shows two of the three guns corresponding to beam paths 8, 9 and a single mounting post 10 for clarity, but is understood to have three guns arranged symmetrically in the pattern seen from the plan view of disc 11 of FIG- URE 2. In essence, the three beams 7, 8 and 9 converge under influence of electrode 12 operating in all three beams together with the orientation of the guns to form a combined three beam grouping that can be deflected in union in a shadow-mask type color tube, for example. Each gun assembly comprises a series of cylindrical electrodes such as 14, 15, 16 and 17 constituting grids one to four in an electron gun. In accordance with the present invention these electrodes are held in apertures 18, 19, 20 an array of matrix holders such as 11 to provide a fixed spaced arrangement having proper orientation to converge the several beams. Thus, each cup electrode is held by a corresponding matrix holder in fixed spaced relationship .and inclination so that all beams in all assemblies are uniform, even when assembled with separate electrode parts.

Consider the difference in hole spacings required between the matrix electrode holders 11, 21, 31 and 41 which form the convergence pattern of the guns in encompassing the corresponding electrodes 14, 15, 16, 17 etc. The matrix holders 11, etc. may be affixed to a set of glass posts through a series of indented tongues 22 for attaining longitudinal spacing along the length of the beams 7, 8, 9.

Each electrode may comprise a metallic cup with beam passing aperture which is seated in apertures 18, etc. so that the appropriate electrical connections may be made to the electrodes in each gun as required. The discs may be insulators for separating guns, or conductive when a common electrode potential is used on all three guns.

When very close spacing tolerances are required, a ceramic disc 21 may be used with registered indentations on opposite sides to receive electrodes 14 and 15 in spaced relationship. In other cases, the mounting matrix disc 41 may be commonly welded at a mid position to electrode 17 with enough precision in spacing to ascertain the re quired uniformity between beams.

While mounting in glass post 10 is a conventional technique which can be accomplished within required longitudinal spacing tolerance, more careful control is afforded as shown in the embodiment of FIGURE 3. This is accomplished by spac ng ceramic cylinders 21', 11, 31 and 41' from each other by means of metallic rings 50 brazed thereto with conventional techniques. Each ring may be seated in a mating indentation 51 if desired to assure completely accurate alignment that will not vary from gun to gun.

Accordingly, it may be recognized that by this novel gun structure an improved gun assembly is provided with features of novelty claimed as follows.

What is claimed is:

l. A three-beam electron gun for a cathode ray tube comprising in combination, a series of integral electrode holders each having three spaced apertures therein, metallic cylindrical electrode inserts aflixed into each of said apertures for forming and accelerating three cathode ray beam in a single direction along separate beam axes extending through each corresponding set of one of the apertures in each holder, and means mounting a plurality of said holders in spaced relationship to define a multiplicity of individual beam paths through respective aligned sets of said spaced cylindrical electrode inserts in said apertures.

2. A three beam electron gun comprising in combination, a series of integral electrode holders each having three spaced apertures therein, metallic cylindrical electrode inserts aflixed in said apertures for forming and directing a beam through each aperture, and means mounting a plurality of said holders in spaced relationship to define a multiplicity of individual beam paths through respective aligned sets of said spaced cylindrical electrode inserts in said apertures, wherein the electrode holders are ceramic cylinders and the means mounting said holders comprises at least one metallic spacer ring affixed between adjacent holders.

3. An electrode holder in .a multiple-beam electron gun comprising an insulating disc, a series of oriented indentations on one side of said disc, a series of registered oriented indentations on the opposite side of said disc, aperture communication means through said disc between the registered indentations smaller than the indentations to provide a spacer portion, and electrodes inserted into said indentations on both sides of said disc to abut said spacer portion to process and orient a plurality of beams in the respective registered indentations of said series while maintaining a predetermined inter-electrode spacing between the electrodes on opposite sides of said spacer portion.

4. An electron gun as defined in claim 2 wherein at least two ceramic cylinders have an indentation mating with the spacer ring, and the spacer ring is seated into the mating indentations between said two ceramic cylinders,

5. A three beam electron gun comprising in combination, a series of integral electrode holders each having three spaced apertures therein, metallic cylindrical electrode inserts affixed in said apertures for forming and directing a beam through each aperture, and means mounting a plurality of said holders in spaced relationship to define a multiplicity of individual beam paths through respective aligned sets of said spaced cylindrical electrode inserts in said apertures, wherein at least one electrode holder is an insulated disc with three indentations on one side of the disc registered with three indentations on the opposite side of the disc and joined by an aperture, and with the electrode inserts aflixed in both indentations on respective sides of the disc, the indentations thereby establishing the inter-electrode spacings between the electrode inserts in said indentations on opposite sides of said disc.

6. An electron gun providing three converging beam paths comprising in combination, a plurality of integral electrode holders each having three spaced apertures therethe apertures along axes converging through the successive holders as the beam moves away from the electron source.

References Cited by the Examiner UNITED STATES PATENTS 2,482,766 9/ 1949 Hansen et a1 3l3-70 References Cited by the Applicant UNITED STATES PATENTS 2,625,734 1/1953 Law.

2,803,768 8/ 1957 Hoagland.

2,859,378 11/1958 Gundert et a1.

2,887,598 5/ 1959 Benway.

2,899,579 8/ 1959 Geer.

2,957,106 10/1960 Moodey.

3,024,380 3/ 1962 Burdick.

3,076,910 9/ 1965 Giutfrida.

DAVID J. GALVIN, Primary Examiner.

ROBERT SEGAL, Assistant Examiner. 

6. AN ELECTRON GUN PROVIDING THREE CONVERGING BEAM PATHS COMPRISING IN COMBINATION, A PLURALITY OF INTEGRAL ELECTRODE HOLDERS EACH HAVING THREE SPACED APERTURES THEREIN AT DIFFERENT SPACINGS THEREBETWEEN, A METALLIC CYLINDRICAL ELECTRODE INSERTS WITH BEAM PROCESSING APERTURES THEREIN AFFIXED INTO EACH OF SAID APERTURES IN THE HOLDERS FOR FORMING AND DIRECTING THE RESPECTIVE BEAMS THROUGH CORRESPONDING APERTURES OF THE ELECTRODE INSERTS IN EACH HOLDER, AND MEANS MOUNTING THE PLURALITY OF SAID HOLDERS SUCECESSIVELY ALONG THE BEAM PATHS IN SPACED RELATIONSHIP WITH THE APERTURES ALONG AXES CONVERGING THROUGH THE SUCCESSIVE HOLDERS IN THE BEAM MOVES AWAY FROM THE ELECTRON SOURCE. 